A typical prior-art intravenous (IV) fluid delivery system is shown in FIG. 1. FIG. 1 shows a reservoir 1, which is hung from a pole 2, a volume metering device 3, which is attached to the reservoir 1 by an IV line 4, and a pump 5, which is clamped to the pole 2 and through which the IV line 6 passes. The IV line 4 may consist of a spike attached directly to the metering device 3 or a spike attached to one end of a short intravenous tube, the other end being attached to the metering device 3. The spike itself is a short, straight, plastic tube with its end cut at an angle to form a sharp point capable of penetrating the seal of the reservoir and thereby opening the delivery port. Spikes tubes known in the prior art are typically less than 10 cm (3 or 4 inches) long. Typical prior-art pumps 5 are large, heavy peristaltic pumps, which operate by peristaltic action on the IV tube 6. To enable the patent to walk around, the pole 2 is typically mounted on a base having casters. The weight of the pump 5 by itself makes it difficult for the patient to walk around without the help of a pole mounted on casters; in addition, many prior art pumps must be plugged into a wall socket. The combined height of the reservoir 1, the volume metering device (normally a flexible drip chamber) 3 and the pump 5 is typically 45-90 cm (18-36 inches).
Other prior art support structures for intravenous fluid delivery systems are described in the following four patents.
U.S. Pat. No. 4,850,560 to Ross discloses an adjustable hanger for hanging an intravenous fluid reservoir. The hanger includes an arm having a suspension member, and has an opening for receiving a hanger support frame. A plunger is slidably mounted on the arm, and a biasing element is interposed between the arm and the plunger for biasing the plunger against the support frame for locking the adjustable hanger in a desired position. In a preferred embodiment, the plunger includes a button, the arm includes a finger tab and the suspending member may be in the form of a hook which includes a finger support portion.
U.S. Pat. No. 4,706,368 to Crissman discloses a method for supporting the drip chamber of an apparatus for intravenous fluid delivery that overcomes the problems encountered when the flow sensor and the drip chamber to which it is attached become tilted during use. The method includes mounting the sensor to the support pole with a bracket. The method includes "providing a rigid support bracket having an elongated arm section, a first clamping member adapted to be removably secured to said IV pole, and a second clamping member adapted to be removably secured to said flow chamber."
U.S. Pat. No. 4,699,296 to Schrock discloses a dispensing device for intravenous injection of fluids into a patient comprising a cradle member for supporting a disposable aseptic rectangular package of fluid, a dispensing device including hollow needles for piercing the package to access the fluid, and a level indicator for indicating the amount of fluid in the package. The cradle has a hanger member which in a preferred embodiment is a hook.
U.S. Pat. No. 1,084,753 to Owens discloses an intravenous apparatus which enables the operator to observe and regulate the flow of solution into a vein. The apparatus includes two glass containers, a first container for holding sterilized water and a second container filled with solution to be injected into the vein. A short tube extending upward into the second container protects against the entrance of foreign particles into the needle. An air ingress tube in the bottom of the first container allows bubbles of air to rise visibly through the sterilized water and enter a closed volume defined by the two containers such as to replace solution flowing from the second container. The bubbles provide an indication of solution flow into the vein.
Similar support structures are used for supporting the components of medical fluid delivery systems for other purposes such as proctotherapy. The following five patents describe prior art relevant to the present invention.
U.S. Pat. No. 4,769,015 to Bloxom discloses a mounting assembly for use in the adjustable supporting of various components of a colonic irrigation or flushing apparatus of the type which directs irrigating fluid by gravity. The mounting assembly includes an elongated base having a plurality of connecting elements on which various components, such as the supply container and monitoring device are supported and further, wherein the connecting elements are structured for selective movement and placement thereof along the length of the base so as to properly position the supply container, monitoring device and depending conduit and introduction element in a preferred location relative to one another and the user of the apparatus being treated.
U.S. Pat. No. 4,425,123 to Di Salvo discloses a parenteral liquid application apparatus that provides for controlled application of parenteral fluid to a patient, in which the fluid is supplied from a flexible bag which changes its volume as the fluid is withdrawn therefrom. The apparatus includes a stationary support pole having a support arm at the top of the pole. A reservoir is suspended from the support arm. A drip chamber is mounted directly beneath the reservoir and the drip chamber and a flow stabilization device are mounted to a scale carrier which is slidably and adjustably mounted to the pole.
U.S. Pat. No. 3,756,237 to Chittenden discloses an irrigation solution administration system including a flexible-pouch reservoir positioned for parallel flow of fluid from a solution container and the reservoir to the instrument being used. The reservoir is placed in-line with the tubing connecting the solution container and the delivery instrument by means of a "Y" type connector. Two solution containers may be provided so that as one container is emptied, it can be replaced while flow continues through a second container. Both containers and the reservoir may be suspended from a horizontal pole-mounted arm. Solution flows by gravity and the reservoir assists in maintaining a constant pressure head.
U.S. Pat. No. 3,625,211 to Butler discloses an apparatus for administering to a patient a pre-measured volume of parenteral solution from a prime fluid supply. The apparatus includes a fluid reservoir, a measuring chamber below the reservoir, a drip barrel below the chamber and a two-way valve connected between the measuring chamber and the drip barrel, connected by a tube to the reservoir. The valve arrangement prevents the possibility of the prime fluid supply being connected directly to the patient and enables repeat administration without manipulation of an antiairentrainment valve.
U.S. Pat. No. 1,572,043 to Schellberg discloses a portable apparatus for use in proctotherapy comprising a plurality of holding receptacle flasks, a distribution system including flexible tubes and a multiported distributing valve all supported by a supporting member having a ring-tube body with extended arms adapted to support the flasks, the tubes and the distribution valve. In a preferred embodiment the supporting member stands on a tripod with caster rollers. An irrigation fluid is delivered to the intestine by gravity.
None of the above described systems provides a compact, portable intravenous fluid delivery system such as provided by the present invention.